Superheater



E. H. FOSTER. SUPERH'EATER. APPLICATION FILED NOV-14', 191's.

Patented May 23, 1922?.-

OMWOMO o o o J w 4,,

. fwemfor; W 2% a/I7 TTUE If" the ERNEST H. FOSTER, 0F DONGAN HILLS,NEVI YORK, ASfiIG-NOB; TO FOWER SPECIALTY COMPANY, OF NEW YORK,

A CORPORATION CF NEW YORK.

SUIPERHEATER.

Application filed November 14, 1919.

To all whom it may come/"1t:

Be it known that I, Emvns'r H. Fos'rnn, a citizen of the United Statesof America, residing at Dongan Hills, Richmond County, and State of NewYork, have invented certain new and useful Improvements in Superheaters,of which the following is a full, clear, and exact description.

In a patent which I obtained in July 9, 1918, No. 1,272,248, asuperheater for steam boilers is shown as located in the combustionchamber at the rear of a return flue tubular boiler, and thisarrangement is typical of a class of boilers in which substantiallysimilar conditions obtain.

To this arrangement certain well defined objections lie. The supportingmeans for the superheater are expensive; the superheater occupiesvaluable space in the rear of the boiler and thereby presents readyaccess to the boiler tubes for inspection and repair; it issomewhatdiflicult to control the amount of superheat which involvescutting out of superheat surface which is an expensive operation; thereis apt to be interference with the usual piping arrangement of theboiler blow-oil, and there is a certain amount of interference with theflow of the gases through the rear passage which can only be avoided byincreasing the depth of the chamber or space at the rear of the boiler.

Generally speaking, therefore, the association with boilers of this typeof superheaters is an engineering problem which, for its accomplishmentin an economical and eflicient manner is by no means easy of solution.Working on such problem I have devised a plan which overcomes theobjections heretofore noted and which secures certain very marked andimportant advantages.

According to this, my invention, I place the superheater for boilers ofthis type under the rear portion of the shell. of the boiler and back ofthe bridge-wall arranging the superheater elements in horizontal rows,and

so arranged that a portion of the gases from the fire after having beenexposed to the cooling effect of the boiler shell, are forced or arecaused to pass over and sweep the superheater tubes.

By this disposition, I am not only enabled to use much simpler andcheaper supports for the superheater, but I may regulate the amount ofsuperheat readily and perfectly Specification of Letters Patent.

Patented May 23, 1922.

Serial at. 337,955.

by the use of a heat resisting slab or plate which may be moved more orless over the supelheater and thus control the volume of hot gases'whichpass over its tubes.

This in'iprovement is illustrated in the accompanying drawings in whichFig. 1 is a view in elevation of the rear of a return tubular boilerequipped with a superheater in the manner above set forth, the settingbeing shown in section; and

Fig. 2 is a vertical section on the line AA of Fig. 1.

The numeral 1 indicates a typical form of return tube boiler, 2 is thesetting and 3 is the bridge-wall common in this class of furnace. Thesuperheater, the tubes of which are designated by the numeral 1, ismounted on supports 8 and 9 back of the bridge-wall and under the rearportion of the boiler 1.

The superheater tubes are supported horizontally and are connected inthe usual manner to headers 12, and are connected at one end by a steaminlet pipe 5 from the boiler and at the other end by an outlet pipe 6 tothe steam main.

Substantially on a. level with the top of the bridge-wall 3 is a slab ofinfusible material 7, which is movable over the superheater to a desiredextent and which may be adjusted to project more or less into the pathof the gases, the direction of which is shown by the arrows 18, and thusregulate the volume of such gases that sweep the superheater tubes.

In all other respects the construction follows well known lines. Theboiler is supported by brackets 10 resting on ledges in the setting 2,and in the rear wall of the setting is the usual access door to thecombustion chamber.

The hot gases from the grate sweep first the boiler surface and thenenter the chamher at the rear. After rounding the rear edge of the slab7, they pass in part downward and over the superheater tubes and thenceupward to the rear of the boiler and then. through the boiler tubes. Bythis means it has been demonstrated by installations in actual use thatas high a degree of superheat as the most exacting conditions demand maybe readily obtained, and the arrangement of the steam inlet and outlettubes 5 and 6 in the direct path of the hot gases contributes to thisresult. The superheater supports are entirely independent of the boilerand may be of simple and cheap construction and character.

Having thus described my l11V11tlO11,Wl121i3 I new claim is:

1. The combination with a return tubular boiler, its settin and a bridgewall under the forward part of the boiler, of a super"- heater with itstubes arranged in horizontal rows back of the bridge wall and directlyunder the rear portion of the boiler, and a slab of infusible materialniorable in line with the boiler and placed over the headers at theforward end of the superheater for regulating by the extent of itsrearward movement over said headers the volume of that portion of thehot gases after they have passed over the forward portion of the boilerthat will flow downwardly and then upwardly over the superheater tubes.

2. The combination with a return tubular boiler, its setting, and abridge wall under the forward part of the boiler, of a superheater withits tubes in horizontal rows, placed back of said bridge wall anddirectly under the rear portion of the boiler, headers for saidsuperheaters adjacent the bridge wall, and a slab of infusible materialplaced over the headers for protecting them from the direct action ofthe furnace gases which. after passing over the forward portion of theboiler flow downward and then upward over the super-heater tubes.

In testimony whereof I hereunto aiiix m y signature.

ERNEST H. FOSTER,

